Ridley is a high-ranking Space Pirate, the archenemy of Samus Aran, and one of the most common recurring characters in the Metroid series, appearing in most of the games. Sadistic and bloodthirsty, Ridley delights in death and destruction, and was responsible for the massacre of the colony K-2L. Since then, he and Samus have clashed several times, with Samus usually emerging the victor. But Ridley's brutality is matched only by his resilience, and he regularly returns from apparent death to do battle with Samus once more. As such, the Space Pirate leader is fittingly referred to as the Cunning God of Death in his Zero Mission official art on the Japanese website. Resembling a skeletal dragon with glowing eyes, the true name of Ridley's species is unknown. Despite his bestial appearance, Ridley is known to be highly intelligent and even shown to be capable of speech in the Magazine Z manga. He was also apparently capable of building a robot in his own likeness. Though Ridley often appears in different forms, it is clarified through scans found in the Metroid Prime series, as well as events portrayed in Metroid: Other M, that every one of his incarnations chronologically seen prior to Other M and Metroid Fusion are indeed the same individual, despite his numerous defeats. Strangely, some of his prior battles ended with his body seemingly exploding, but in-game lore states he survived these violent defeats until Super Metroid. In most games he appears in, he has been the penultimate or ante-penultimate boss.
He is voiced by Steve Blum in the English dub and Daisuke Hirakawa in the Japanese dub.